1. Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea
2. Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Korea
3. Department of Radiation Oncology, Chonnam National University Hwasun Hospital, Hwasun, Korea
4. Department of Radiation Oncology, Dong-A University Hospital, Dong-A University College of Medicine, Busan, Korea
5. Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
6. Department of Radiation Oncology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Korea
7. Department of Radiation Oncology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea
8. Department of Radiation Oncology, Gachon University Gil Medical Center, Incheon, Korea
9. Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
10. Department of Radiation Oncology, Pusan National University School of Medicine, Busan, Korea
11. Department of Radiation Oncology, Bundang CHA Medical Center, CHA University, Gyeonggi-do, Korea
12. Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea
13. Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea
14. Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea